The F-Series is a series of full-size pickup trucks from Ford Motor Company which has been sold continuously for over six decades. The most popular variant of the F-Series is the F-150. It was the best-selling vehicle in the United States for 24 years, currently (2007) the best-selling truck for 37 years, and the best selling vehicle in Canada, though this does not include combined sales of GM pickup trucks. In the tenth generation of the F-series, the F-250 and F-350 changed body style in 1998 and joined the Super Duty series.